OPTIONAL: Mechanical Engineering (strategy, booklist,problems and soln)

Anyone clearing prelims (or likely to clear pre) with mech optional?

If anybody has question papers of any mock tests by NextIAS or Made easy, please share. Even if it’s from last year or before that. TIA

Guys, any idea about how the marks were in mains 2019 for mech? A lot of optionals got screwed I heard